U.S. patent application number 12/633508 was filed with the patent office on 2010-06-17 for meteorological modelling method for calculating an aircraft flight plan.
This patent application is currently assigned to Thales. Invention is credited to Xavier Blanchon, Francois Coulmeau, Antoine Lacombe.
Application Number | 20100152931 12/633508 |
Document ID | / |
Family ID | 40848750 |
Filed Date | 2010-06-17 |
United States Patent
Application |
20100152931 |
Kind Code |
A1 |
Lacombe; Antoine ; et
al. |
June 17, 2010 |
Meteorological Modelling Method for Calculating an Aircraft Flight
Plan
Abstract
The invention relates to a meteorological modelling method for
calculating an aircraft flight plan, the aircraft comprising a
communication means and a navigation management system. The method
comprises at least the following steps: the communication means
carries out the acquisition of meteorological prediction data
related to waypoints in proximity to the nominal route in addition
to the waypoints belonging to the nominal route, the navigation
management system allocates by projection onto the current route of
the aircraft the prediction data for the said waypoints not
belonging to the current route, the navigation management system
calculates the meteorological prediction data for the waypoints of
the current route of the flight plan according to the prediction
data allocated by projection onto the current route of the
aircraft. The invention is a modelling method for aircraft
navigation management systems.
Inventors: |
Lacombe; Antoine; (Monferran
Saves, FR) ; Blanchon; Xavier; (Toulouse, FR)
; Coulmeau; Francois; (Seilh, FR) |
Correspondence
Address: |
LARIVIERE, GRUBMAN & PAYNE, LLP
19 UPPER RAGSDALE DRIVE, SUITE 200
MONTEREY
CA
93940
US
|
Assignee: |
Thales
Neuilly Sur Seine
FR
|
Family ID: |
40848750 |
Appl. No.: |
12/633508 |
Filed: |
December 8, 2009 |
Current U.S.
Class: |
701/8 |
Current CPC
Class: |
G08G 5/0091 20130101;
G01W 1/10 20130101; G08G 5/0039 20130101; G05D 1/0202 20130101;
G01W 1/08 20130101 |
Class at
Publication: |
701/8 |
International
Class: |
G01C 23/00 20060101
G01C023/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 9, 2008 |
FR |
08 06902 |
Claims
1. Meteorological modelling method for calculating an aircraft
flight plan, the said flight plan being made up of a route
comprising a plurality of waypoints interconnected by segments and
each of the waypoints being associated with meteorological
prediction data, the aircraft comprising a communication means
carrying out the acquisition of the meteorological prediction data
related to the waypoints and a navigation management system
computing a nominal route before departure, as well as alternative
routes while in flight, and guiding the aircraft on a trajectory
following the current route of the flight plan, comprising at least
the following steps: the communication means carries out the
acquisition of meteorological prediction data related to waypoints
in proximity to the nominal route in addition to the waypoints
belonging to the nominal route; the navigation management system
allocates according to an orthogonal projection onto temporary
points distinct from the waypoints of the current route or of the
trajectory of the aircraft the value of the meteorological
prediction data for the waypoints not belonging to the current
route; the navigation management system calculates the
meteorological prediction data for the waypoints of the current
route or the trajectory of the flight plan according to the
prediction data for the points, allocated by projection onto the
current route of the aircraft.
2. Method according to claim 1, wherein the current route of the
aircraft is an alternative route to the nominal route.
3. Method according to claim 1, wherein the communication means
carries out the acquisition of meteorological prediction data
originating from a plurality of meteorological data sources.
4. Method according to claim 3, wherein the navigation management
system selects prediction data related to waypoints whose distance
of deviation from the current route of the flight plan is less than
a distance threshold.
5. Method according to claim 4, wherein the distance threshold is
parametrizable according to the number of prediction data
acquired.
6. Method according to claim 4, wherein the value of the threshold
is calculated dynamically along the nominal route as a function of
the density of data acquired along the nominal route.
7. Method according to claim 2, wherein the communication means
carries out the acquisition of meteorological prediction data
originating from a plurality of meteorological data sources.
8. Method according to claim 7, wherein the navigation management
system selects prediction data related to waypoints whose distance
of deviation from the current route of the flight plan is less than
a distance threshold.
9. Method according to claim 8, wherein the distance threshold is
parametrizable according to the number of prediction data
acquired.
10. Method according to claim 8, wherein the value of the threshold
is calculated dynamically along the nominal route as a function of
the density of data acquired along the nominal route.
11. Method according to claim 1, wherein the points of the current
route, on which meteorological prediction data are allocated, are
points calculated temporarily for the duration of the flight and
specifically for the meteorological modelling method.
Description
PRIORITY CLAIM
[0001] This application claims priority to French Patent
Application Number 08 06902, entitled Meteorological Modelling
Method for Calculating an Aircraft Flight Plan, filed on Dec. 9,
2008.
FIELD OF THE INVENTION
[0002] The field of the invention relates to schemes for
calculating an aircraft's flight plan prediction data. In
particular, the invention is a meteorological modelling method for
calculating the flight plan, notably for modelling the profile of
the winds of the navigation management system onboard the
aircraft.
BACKGROUND OF THE INVENTION
[0003] In recent years the increase in traffic and the resulting
load on air traffic control has led to efforts to improve flight
prediction systems so as to guarantee the safety but also the
economic viability of air transport. Meteorological uncertainties
are the main causes of time related vagaries when calculating
flight plans. The navigation management systems of aircraft, more
commonly called FMS for "Flight Management System", calculate
prediction data such as flight time and fuel consumption for
example. These prediction data are determined by means of a
calculation method taking the weather as one of the input factors,
notably with data about winds, temperatures and pressure. These
data have a big impact on the results of the prediction models.
Indeed, for calculating the flight time of an aircraft for example,
the ground speed taken into account is equal to the vector sum of
the speed of the aeroplane and of the speed of the wind. Currently,
the wind data provided to aeroplanes represent samples of points
according to altitude slices.
[0004] In the environs of airports, it will for example be
considered that the points of the takeoff and landing procedures
are encompassed in a purely vertical wind model, based on altitude
(at Iso altitude the wind is the same for the points of the
procedure). On the "En route" or "cruising" part, a model which is
at one and the same time vertical (based on altitude slices) and
longitudinal (along the points of the flight plan) is generally
considered, the longitudinal aspect being due to the fact that the
wind can vary along the flight, all the more when travelling large
distances.
[0005] For calculating wind profile over the route, from a
departure airport to an arrival airport, weather ground stations
transmit the wind data to the subscriber airlines, and the latter
format them by altitude slices for the climb phase, the descent
phase and the cruising flight phase so as to construct the paper
pilot briefing or else to dispatch them to the aeroplanes in vocal
or numerical form. The numerical wind data are transmitted
according to the ARINC 702A standard (AEEC 702A "Flight Management
System") and are decoded aboard the aircraft by a communication
management system, commonly called CMU for "Communication
Management Unit", or by another system such as the navigation
management system, or else partially by one and then completed by
the other. The aircraft navigation management system determines a
predictive nominal route according to a lateral trajectory and a
vertical trajectory to reach the arrival airport. This predictive
nominal route is defined by a plurality of waypoints and by
segments of trajectories between these waypoints, commonly called
"legs". The route can optionally contain elements other than the
waypoints so as to construct the legs of the terminal procedures.
These elements are standardized on board by ARINC 424 (AEEC 424:
Navigation Data Base). The subsequent description will use the
terms waypoint and leg which are customarily used in the field of
aeronautics. Waypoints are catalogued in published navigation
databases meeting the ARINC-424 standard which make it possible to
define the most common aerial routes.
[0006] By collaboration of the positioning, guidance and navigation
management systems, the aircraft follows the programmed trajectory.
The navigation management system then calculates the prediction
data in part as a function of the wind data for each waypoint of
the aircraft's forecast nominal route. The entry of the
meteorological data into the FMS for calculating the flight plan
prediction data can be entered manually by the pilot or entered
automatically by downloading the data by datalink.
[0007] The wind data are in general loaded aboard the aircraft
before its departure for each waypoint of the nominal route or for
a few elements, the aim being to forecast the fuel load to be
carried and the flight time. These meteorological data constitute a
predictive snapshot of the meteorological situation, the scope of
which is reduced to the reference trajectory of the aircraft. The
meteorological data transmitted aboard the aircraft represent a
static forecast of the meteorological situation.
[0008] When an aircraft in flight encounters an unfavourable
meteorological situation which is not in accordance with the
forecast meteorological situation, for example a cloud under
formation or a storm, the pilot may be constrained to deviate
slightly from the reference trajectory. Likewise, the aeroplane may
have deviated from its forecast trajectory for other reasons such
as air traffic constraints, a diversion on account of a fault
and/or an event on board such as a sick passenger, etc. From the
moment the pilot leaves the nominal route, he is constrained to
abandon the nominal flight plan and to compute an alternative
flight plan.
[0009] In the prior state of the art, the alternative flight plan
is built on the basis of just the meteorological data available in
the aircraft, that is to say on the basis of the data which
constitute the predictive snapshot. The FMS rejects the winds
received by datalink if they do not correspond to a waypoint of the
flight plan since the current specifications are based on a wind or
a temperature per waypoint. These data which constitute the
predictive snapshot are, by construction, unsuitable since they are
values associated with places or with dates which do not
correspond, a priori, to the waypoints of the alternative flight
plan. Nevertheless, in spite of their unsuitability, they are
meteorological data which are taken into account when determining
the alternative flight plan by making an implicit assumption of
stability of the data.
[0010] Taking erroneous meteorological data into account when
establishing an aircraft route plot can have, at the margin,
important consequences for flight safety, and more frequently, an
impact on the pilot's ability to compute an alternative route that
he will actually be able to follow right to the end without any
fuel problem. The latter drawback is all the more deleterious as
punctuality of civilian passenger transport aeroplanes is on the
way to becoming an important issue for airlines and consequently
for aircraft pilots because of the policy followed by air traffic
control bodies which is aimed at optimizing the use of airports by
imposing, potentially subject to financial sanction, precise dates
of transit for passing predefined points in space.
[0011] In the future, it is envisaged that airlines will be
provided with a winds publication service in the form of a
three-dimensional mesh of the airspace. However, to set up such a
service, future systems require the deployment of new ground
structures for recovering and dispatching wind data as well as new
devices onboard aircraft. There will also be a standardization step
to allow an exchange between the various players on the ground and
on board.
SUMMARY OF THE INVENTION
[0012] An important aim of the invention is to alleviate the
aforesaid problems. To achieve this aim, the invention proposes a
meteorological modelling method for calculating an aircraft flight
plan, the said flight plan being made up of a route comprising a
plurality of waypoints interconnected by segments and each of the
waypoints being associated with meteorological prediction data, the
aircraft comprising a communication means carrying out the
acquisition of the meteorological prediction data related to the
waypoints and a navigation management system computing a nominal
route before departure, as well as alternative routes while in
flight, and guiding the aircraft on a trajectory following the
current route of the flight plan. The method is characterized in
that it comprises at least the following steps:
[0013] the communication means carries out the acquisition of
meteorological prediction data related to waypoints in proximity to
the nominal route in addition to the waypoints belonging to the
nominal route;
[0014] the navigation management system allocates by projection
onto points of the current route or of the trajectory of the
aircraft the prediction data for the said waypoints not belonging
to the current route;
[0015] the navigation management system calculates the
meteorological prediction data for the waypoints of the current
route or the trajectory of the flight plan according to the
prediction data for the points, allocated by projection onto the
current route of the aircraft.
[0016] Before the departure of the aircraft, the communication
management system loads the wind data for waypoints of the nominal
route but also the data relating to the waypoints of the
geographical zone over which the aircraft has forecast it will
operate.
[0017] A characteristic of the method is that the communication
means carries out the acquisition of meteorological prediction data
originating from a plurality of meteorological data sources. These
data can originate from company data and/or from meteorological
data suppliers and the meteorological prediction data are, in
particular, wind data.
[0018] A characteristic making it possible to reduce the
calculation times of the modelling method and to increase the
precision of the flight plan prediction data is that the navigation
management system selects prediction data related to waypoints
whose distance of deviation from the nominal route of the flight
plan is less than a distance threshold.
[0019] In one mode of realization, the distance threshold is
parametrizable according to the number of prediction data
acquired.
[0020] In one mode of realization, the value of the threshold is
calculated dynamically along the nominal route as a function of the
density of data acquired along the nominal route.
[0021] Advantageously, for the meteorological method of flight plan
modelling, the current route of the aircraft is an alternative
route to the nominal route. The invention makes it possible to
recalculate a wind profile for an alternative route of the flight
plan. The system having previously loaded wind data for the
waypoints surrounding the nominal route, when the navigation
management system computes a new flight plan for an alternative
route, it uses as input data the wind data existing in the system
for these new waypoints if they exist, though it is very improbable
that they will have been loaded previously, and/or the wind data
for the surrounding points.
[0022] The wind data allocated to the waypoints which have no wind
data initially loaded arise from wind data situated in proximity to
the waypoint and are the result of a calculation of a mean by
weighting several waypoints. Several modes of implementing the step
of allocating a wind datum value to a waypoint can be carried out
and will be described subsequently in the description.
[0023] Another advantage is the possibility of defining a more
precise wind profile sampling increment, since the invention makes
it possible to allocate a wind prediction datum for every waypoint
of the flight plan. By computing a flight plan route with numerous
waypoints, the navigation system consequently has available to it a
wind profile comprising a larger number of data samples.
[0024] Another advantage is that the invention does not require any
additional ground structure providing for example a service of 3D
meshing of the airspace an as to allocate a wind datum to every
waypoint of the flight space surrounding the nominal route.
Moreover, the aircraft is also not constrained to have specific
onboard equipment, the modelling method possibly being carried out
by the existing navigation management system and the wind data
necessary for the calculation may also be recovered by the existing
communication management system.
[0025] In one mode of calculation, the navigation management system
allocates according to an orthogonal projection onto temporary
points of the current route the value of the meteorological
prediction data for the waypoints not belonging to the current
route. The said points of the current route, on which
meteorological prediction data are allocated, are points calculated
temporarily for the duration of the flight and specifically for the
meteorological modelling method.
[0026] In a second mode of calculation, the navigation management
system allocates the value of the meteorological prediction data
for waypoints not belonging to the current route to the waypoints
of the current route not comprising any initially allocated
meteorological prediction data.
[0027] The invention also relates to the navigation management
system for an aircraft making it possible to calculate a flight
plan between the departure airport and the arrival airport. The
system is characterized in that to compute the flight plan
prediction data, the said system carries out the meteorological
modelling method such as described in any mode of realization
above.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The invention will be better understood and other advantages
will become apparent on reading the description which follows given
without limitation and by virtue of the appended figures among
which:
[0029] FIG. 1 represents a chart of a mode of progression of the
method for calculating the predictive data of a flight plan for
aircraft. This chart illustrates particularly the method of
meteorological modelling of the wind data.
[0030] FIG. 2 illustrates the step of selecting the wind data
around the current route of the flight plan of the aircraft, the
stars representing the waypoints of the current route and the
arrows representing wind data loaded for waypoints of the
geographical zone surrounding the current route. The figure
illustrates a first mode of selecting or filtering the wind data,
carried out according to a threshold of distance with respect to
the current route of the flight plan.
[0031] FIG. 3 represents a second mode of selecting the wind data,
carried out according to a threshold of distance with respect to
the waypoints of the current route.
[0032] FIG. 4 represents a first mode of allocating the wind data
related to waypoints not belonging to the current route of the
flight plan. The figure represents a mode of allocating the wind
data by orthogonal projection onto the current route.
[0033] FIG. 5 represents a second mode of allocating the wind data
related to waypoints not belonging to the current route of the
flight plan. The figure represents a mode of allocating the wind
data by projection onto the waypoints of the current route of the
flight plan.
[0034] FIG. 1 illustrates the method of calculating the flight plan
prediction data, in particular the part for modelling the wind
prediction data. The onboard navigation management system, FMS, of
an aircraft is the computer which determines the geometry of the
trajectory profile in 4D, that is to say over the three-dimensional
geographical space and time (via the speed profile). The FMS
dispatches the guidance directives for following this profile to
the pilot or to the automatic pilot. The functions computed by an
FMS system are described in the ARINC 702 standard.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
[0035] In a first phase symbolized by step 1 of FIG. 1, at the
moment of departure the flight plan is input by the pilot on the
basis of data contained in the navigation database. The pilot
enters several aircraft parameters: the weight, the flight plan,
the span of cruising levels and one or more of the optimization
criteria. These input data allow the functions of the FMS to
calculate respectively the lateral trajectory and the vertical
profile which minimizes the cost.
[0036] In a second phase represented by step 2, the meteorological
data are loaded aboard the aircraft. The pilot can thereafter enter
and/or receive by datalink (ACARS for "Aircraft Communications
Addressing and Reporting System") the meteorological data. The
communication management unit CMU receives the messages coming from
the ground and/or satellites. These messages are thereafter decoded
so as to be utilized by the FMS. These data relate to: [0037] the
wind data on the climb phase relating to the strength and direction
in altitude slices of up to five slices, [0038] the wind data on
the cruising points relating to the waypoints, the strength and
direction in altitude slices of up to six slices, [0039] the wind
data on the descent phase relating to the strength and direction in
altitude slices of up to six slices, [0040] the data regarding the
ground temperature, the temperature at cruising level and the
tropopause altitude, [0041] the data regarding the temperatures
during cruising relating to the temperature, the altitude and the
waypoints, [0042] the data regarding the temperature at the
destination.
[0043] The objective of loading the meteorological data is to
collect the wind data which will be utilized to construct a wind
profile over the current route of the flight plan. The current
route corresponds to the nominal route computed before departure or
to an alternative route. The loaded wind data can originate from a
plurality of sources, a meteorological service related to the
company and/or from a supplier of meteorological data. In
contradistinction to the existing technical solutions, the loading
of weather data relates to the geographical zone of the flight zone
forecast, laterally as well as vertically, and not solely to the
waypoints of the nominal route of the flight plan. The number of
wind data loaded is fairly high since it represents the data for a
geographical space wide enough to integrate any alternative routes
that may possibly be used between the departure airport and the
arrival airport.
[0044] Once the wind data have been loaded, in a third phase the
method preferably carries out a step of selecting the data around
the current route of the aircraft so as to optimize the
calculations. Nevertheless, this step is optional since it can be
avoided if the number of data loaded does not give rise in the
following steps to an overly lengthy calculation process. The
objective of step 3 of filtering the meteorological data is to
optimize the calculations for allocating the meteorological data
over the current route of the flight plan. It in fact makes it
possible to reduce the calculation time for step 4 of allocating
the data and step 5 of calculating the wind profile over the
current route. The selection of the data can be carried out on the
lateral profile and/or vertical profile so as to preserve only the
winds close to the current route of the aircraft.
[0045] In a first mode of realization of the selection of the
meteorological data, represented by FIG. 2, the navigation
management system selects prediction data 13 related to waypoints
11 whose distance of deviation from the current route 10 of the
flight plan is less than a distance threshold. The arrows 13 of the
figure symbolize wind data on the flight plan. The stars 11
symbolize the waypoints of the current route of the flight plan.
The current route is made up of legs 12. The distance threshold 20
delimits a selection zone 21 around the current route 10. The
meteorological data related to a waypoint 13 located inside this
zone are preserved for the calculation of the wind profile and the
data related to a waypoint located outside the selection zone 21
are rejected. For the lateral profile and the vertical profile, the
selection zone 21 is of the form of a rectangular cavity
surrounding the route of the flight plan,
[0046] In a second mode of realization of the selection of the
meteorological data, represented by FIG. 3, the navigation
management system selects prediction data related to waypoints
whose distance of deviation 22 from the waypoints of the current
route of the flight plan is less than a distance threshold. The
selection zones 23 are of the form of spheres, or circles on a
plane, around the waypoints of the current route.
[0047] As a function of the wind data loaded in the course of step
1 of the method for calculating the flight plan, the selection may
be more or less selective. In an optional characteristic of the
method, the distance threshold is parametrizable according to the
number of meteorological prediction data acquired. If few data are
loaded during the data acquisition step, then the distance
threshold 20 or 22 can be increased. In the converse case, the
distance threshold is reduced. The objective of the filtering is to
reduce the number of data samples for the calculations following so
as to avoid a degradation of the wind profile calculation time
without degrading the precision of the calculations.
[0048] In another filtering option, the distance threshold is
dynamic as a function of the density of the prediction data
according to the geographical zones of the current route of the
flight plan. For zones which are dense in wind data, the distance
threshold can be reduced and for zones of lower density the
distance threshold can be increased, the distance threshold
evolving during the progress of the flight plan.
[0049] In a fourth phase, the method of calculating the flight plan
prediction data comprises a step 4 of allocating the value of the
prediction data related to waypoints outside of the current route
of the flight plan on points located on the current route. This
projection-based allocation step makes it possible to obtain a wind
profile over the whole of the flight plan. These points onto which
the prediction data are projected can be waypoints 41 of the route
of the flight plan or points calculated 31 temporarily for the
duration of the flight and specifically for the calculation of the
predictions of the flight plan.
[0050] In FIGS. 4 and 5, the flight plan is a list of legs, also
termed a discrete list. The segments of the flight plan are
straight lines drawn between the legs of the flight plan, sometimes
called the "pseudo-trajectory". The trajectory 50 of the aircraft
is a trajectory equivalent to curves linking the segments of the
flight plan taking into account the transitions between the
straight lines. The allocation calculation is the same for both
these trajectories, but the projection point will be different if
it falls in a transition in terms of position. The projection can
be carried out on the pseudo-trajectory (10) of the flight plan or
on the trajectory segments (50). In FIGS. 4 and 5, the trajectory
50 is represented with a slight shift with respect to the legs for
better understanding of the figures.
[0051] According to a first mode of allocation illustrated by FIG.
4, the wind data 32 can be allocated by orthogonal projection onto
the route to be followed creating points 31 which will be used in
the calculation. The points 31 are not database waypoints, but
calculated points used for the wind model of the predictions. These
are pseudo-waypoints, waypoints created temporarily, over the time
of the flight an as to demarcate wind data which are applied to the
flight plan.
[0052] According to a second mode of allocation illustrated by FIG.
5, the wind data 40 can be allocated by projection onto the
waypoints defining the current route of the flight plan. In this
particular mode, weighting criteria are preferably assigned to each
of the wind projections. These weightings can be used during the
calculation of the prediction data for the winds on the waypoints
or also over the whole of the profile of the flight plan. These
weighting criteria can be the altitude of the wind measurement, the
information source for the wind datum, the distance with respect to
the flight plan, the distance with respect to the position of the
aeroplane or the distance with respect to the waypoints of the
flight plan. These examples of weighting criterion are cited by way
of nonlimiting example.
[0053] In a fifth phase, the method of calculating the flight plan
prediction data comprises a step 5 of calculating the wind data for
the waypoints of the flight plan. These wind data of the flight
plan make it possible to calculate a wind profile over the flight
plan. This wind profile is thereafter intended to be utilized for
the calculation of the whole of the flight plan prediction data,
for example the speed profile, the vertical profile, the lateral
profile, the weight profile and the profile of the transit times of
passing the waypoints of the flight plan. With each waypoint or
characteristic point of the vertical profile ("Top Of Climb", "Top
of Descent" for example) is associated a wind datum. The
calculation of the wind profile can be carried out according to
several schemes: the last wind prediction datum known on the
current route can be used for the following waypoint, the closest
projected wind prediction datum on the current route can be
allocated to the waypoint of the current route, the computer can
also carry out an interpolation between the last known prediction
datum and the following prediction datum on the flight plan or the
computer can allocate to a waypoint a datum predicting the wind by
barycentric interpolation of the wind data projected initially onto
the current route. The weighting criteria used in the previous step
of allocating the data over the current route can be taken into
account for the calculation.
[0054] The calculation scheme based on barycentric interpolation
makes it possible to favour certain wind data with respect to other
data so as to calculate the most reliable prediction resultant.
Moreover, according to the latter calculation scheme the number of
wind data used may be parametrizable statically or dynamically.
This parameter influences the calculation times for generating the
profile. The management of this parameter makes it possible to
adjust the equilibrium between a reasonable calculation time and
the precision of the wind datum calculated.
[0055] Once the wind profile has been determined over the whole of
the current route, in a sixth phase the navigation system
calculates in step 6 the prediction data for the various profiles
of the flight plan, notably the transit times and fuel consumed for
each element of the flight plan, that is to say for each "leg". On
the basis of the wind profile determined, it is possible to
calculate the profiles (time, fuel for example) with respect to the
predictions by using the wind profile. The calculation is carried
out incrementally using a wind which evolves incrementally as a
function of the progress of the aeroplane along the trajectory. In
the calculation of the predictions, when the aeroplane passes a
point, the prediction data, the time, the weight, as well as the
wind used in the calculation at that moment are saved. The wind
profile is displayed on the man-machine interface of the cockpit.
The meteorological modelling method makes it possible to provide as
input to the calculations a more reliable wind profile relating to
the nominal route, since it benefits from a wider wind data
sample.
[0056] The invention is particularly advantageous when an
alternative route to the nominal route is input into the system, as
represented in step 7 of FIG. 1. When loading the wind data before
departure, there is little chance that the wind data for the
waypoints of the alternative route will have been loaded. The
invention nevertheless makes it possible to compute a wind profile
for this new route since the modelling method is capable of
determining a wind profile with data not belonging to the
alternative route. In the case of the inputting of an alternative
route to the nominal route, the modelling method executes all the
steps 2 to 6 to determine a new flight plan according to this
alternative route.
[0057] During the progression of the flight plan, the communication
management system receives wind data by datalink. If the current
route in the navigation management system is still the nominal
route, the external authorities transmit the wind data
corresponding to the waypoints of the current route. However, if
the current route is an alternative route, the external authorities
are not necessarily kept informed immediately of the waypoints of
the alternative route. The invention nevertheless makes it possible
to utilize the wind data not corresponding to the current
route.
* * * * *